PEP primary school sixth grade mathematics volume I elite course 38-39 answers Page 38 4 questions page 39 4.5.6 questions It's urgent, 80 points, thinking, As shown in the figure, AB and BC are ramps. It takes 4 hours for a person to walk from a to B and 45 minutes from B to C. It is known that the speed of a person going up the ramp is 40% of that of a person going down the ramp. How long does it take for a person to go back to a from C through B? This question

PEP primary school sixth grade mathematics volume I elite course 38-39 answers Page 38 4 questions page 39 4.5.6 questions It's urgent, 80 points, thinking, As shown in the figure, AB and BC are ramps. It takes 4 hours for a person to walk from a to B and 45 minutes from B to C. It is known that the speed of a person going up the ramp is 40% of that of a person going down the ramp. How long does it take for a person to go back to a from C through B? This question

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Answers to lesson 22 of PEP's elite course

5： 1. Quick eyes, quick hands and high spirits
3. Own advantage: flexible
Small fat Dun's slightly potential: silly big black thick, spirit turn not move

Problems in the second volume of the sixth grade mathematics course of the people's Education Press
9 questions on page 115:
On a map with a scale of one in four million, the distance between AB and ab is 20 cm. Two trains leave AB at the same time. Car a travels 87 km per hour, and car B 113 km per hour. How many hours do they meet?
10 questions on page 116:
After mixing the two kinds of sugar, the selling price is 12.3 yuan per kilogram. The mass ratio of the two kinds of sugar is calculated
Those who want to answer quickly, detailed additional reward

Let a be x, 14.8x + 10.8 (1-x) = 12.3, x = 0.375, 0.375 / (1-0.375) = 3 / 5

The circumference of an isosceles triangle is 48 cm. The height of the bottom is 3 cm longer than half of the bottom. The length of the bottom of the isosceles triangle is 48 cm

Let the length of the base be x, then the height be x △ 2 + 3, and the Pythagorean theorem is: √ ((x / 2) &# 178; + (x / 2 + 3) &# 178;)
2×√（(x/2）²+（x/2+3）²）+x=48
x²+27×4x-2268=0
（x+126）（x-18）=0
So x = - 126, or x = 18
So the bottom edge = 18cm

A. The masses of B are ma and MB respectively. They are connected by light springs and placed on a rough horizontal plane. Under the action of horizontal force F, a and B accelerate with a, and when the force F is removed
What's the acceleration of a and B?

A is - A
B is a

Excel table formula setting
Operation date product name quantity Card No. label adhesive case adhesive magnet plug in package qualified number
January 2 product 1 1000 2 a 800
January 2 product 5 1000 2 B 900
January 2 product 5 1000 3 C 700
January 2 product 1 1000 3 D 1000
January 2 product 1 1000 4 E 1000
January 2 product 1 1000 4 E 1000
January 2 product 1 1000 5 e 1000
January 2 product 1 1000 5 e 1000
January 2 product 1 1000 5 e 1000
I want the sum of qualified numbers and the ratio of the sum of numbers to set the formula together and ask for the help of experts,

Your quantity is listed in column C, and the qualified number is listed in column J. then use the formula:
=Sum (J: J) / sum (C: C) is enough
If you want to solve the problem by date, use the formula:
=SUMIF (A: A, "= January 2", j: J) / SUMIF (A: A, "= January 2", C: C)
or
=SUMIF (A: A, "=" & M1, j: J) / SUMIF (A: A, "=" & M1, C: C) assume that the date corresponding to the data is in cell M1
If you want to solve the problem by product, use the formula:
=SUMIF (B: B, "= product 1", j: J) / SUMIF (B: B, "= product 1", C: C)
or
=SUMIF (B: B, "=" & M1, j: J) / SUMIF (B: B, "=" & M1, C: C) assume that the product name corresponding to the data is in cell M1

There is a smooth inclined plane with mass m on the horizontal plane. The dynamic friction factor between the inclined plane and the ground is μ. There is an object with mass m acting on the inclined plane with horizontal constant force. There is no relative sliding between the two objects. Find the pressure of the object m on the inclined plane and find the value of F

If we want to do this problem, we must know the angle between the inclined plane and the horizontal plane, just as it is θ
Then the pressure of the object m on the inclined plane is n nsin (θ) = mg n = mg / sin (θ)
F=2Mg tg(θ) +2Mμ

It is known that the general term formula of the first n terms of the arithmetic sequence {an} is Sn, and a1 + a3 = 10, S4 = 24 (1) to find the general term formula of the sequence {an}

a1+a3=10,
S4=24＝a1+a2+a3+a4=2*（a1+a3）+2d=20+2d
d=2
a1+a3=10=2a1+2d
a1=3
So an = an + (n-1) d = 3 + 2 (n-1) = 2n + 1

When an object moves in a straight line with uniform speed change, the velocity is 2m / s at a certain time and 4m / s after 1s
A. The displacement may be less than 2m B. the displacement may be more than 4m
C. The acceleration may be less than 2m / S2 D. the acceleration may be more than 4m / S2 D
Please choose the best answer and write the detailed process. Thank you

Select D
If the two velocity directions are opposite, the displacement is: | x1 | = | V1 + V2 | / 2 = 2m
If the two velocity directions are the same, the displacement is: | x2 | = | V1 + V2 | / 2 = 3M
Similarly, when the direction is the same, a = (v1-v0) / T = 2m / S ^ 2
When the direction is opposite, a = | (v1-v0) / T | = 6m / S ^ 2

March 6 is the rest day for Xiaoming and his parents on the same day. Dad works for 4 days and takes 1 day off. Mom works for 3 days and takes 1 day off. Xiaoming studies for 5 days and takes 2 days off. What's the next time

March 26